Automatic printer stack edge guide alignment information

ABSTRACT

In a typical print media sheets feeding system, sheet stacks of different dimensions are stacked into, and then fed from, a sheet stacking tray having opposing stack edge guides, at least one of which the operator must first manually reposition close to the sides of a stack being newly loaded of different dimensions to insure proper sheet feeding. There is provided here an electronic stack edge guide positioning confirmation system with a repositionable sheet stack edge proximity sensing system repositioning with the repositionable stack edge guide and providing an automatic warning signal against the feeding of sheets if the opposing edge guides are not positioned in close proximity with the corresponding opposing sides of the particular stack of sheet currently loaded in the tray, if the width of the latest loaded stack differs and/or the side guides have not been properly reset to the currently loaded stack size.

Disclosed in the embodiments herein is a system for automatically determining when a different size of paper or other print media has been stacked into a particular paper tray for a printer and/or if the stack side or end guides are properly positioned relative to that stack of print media for good sheet feeding.

By way of background certain known printer products, such as the Xerox Corporation “Igen3”® printer, have sensors that can signal, at least approximately, the respective positions of sheet stack side or end guides in a sheet stacking tray, and a graphical user interface (GUI) that can accept manual operator input of information on the selected tray and paper size to be printed, and controller software that warns the operator by comparisons -of those inputs that the stack guides are not in the correct position for the selected paper size from that tray.

In contrast, the disclosed embodiments do not require, or depend on the accuracy of, any manual operator input of new information on the currently loaded sheet stack dimensions. The disclosed embodiments provide an automatic check and direct confirmation that the stack guides are in fact properly set or reset to be closely adjacent to or contacting the sides of the actual stack loaded into that tray at that time. If a stack of different size sheets is subsequently loaded into that tray and its stack guides have not been reset to those new stack dimensions for proper sheet feeding, and/or proper stack alignment, a potential sheet feeding fault condition may be automatically signaled to the printing system user or operator.

Merely by way of examples of patents on sheet feeding systems involving sheet size sensing and/or repositionable side guide sensing are Xerox Corp. U.S. Pat. No. 5,511,771 issued Apr. 30, 1996 to Robert F. Rubscha; and U.S. Pat. No. 5,946,527 issued Aug. 31, 1999 by David L. Salgado et al.

A specific feature of the specific embodiments disclosed herein is to provide in a sheet stacking tray for stacking print media sheets of different sheet stack dimensions in at least one sheet stacking area for feeding said sheets from said stack with a sheet feeder, said sheet stacking tray having at least one manually repositionable sheet stack edge guide repositionable to provide an edge guide for at least one side of said sheet stack for said different particular sheet stack dimensions, there is provided an electronic stack edge guide positioning confirmation system with a repositionable sheet stack edge proximity sensing system that is automatically repositionable with said at least one repositionable sheet stack edge guide, said electronic stack edge guide repositioning confirmation system providing with said repositionable sheet stack edge proximity sensing system an automatic warning signal against the feeding of said sheets from said stack with said sheet feeder if said sheet stack edge guide has not been positioned in at least close proximity to said at least one side of said sheet stack sheet stack stacked-into said sheet stacking tray.

Further specific features disclosed in the embodiments herein, individually or in combination, include those wherein the sheet stacking tray wherein said electronic stack edge guide repositioning confirmation system is adapted to provide electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of said sheet stack in said sheet stacking tray to substantially engage said at least one side of said stack in said sheet stacking tray; and/or wherein said electronic stack edge guide repositioning confirmation system is adapted to provide electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to said at least one side of said sheet stack in said sheet stacking tray when said at least one side guide is positioned within approximately 2 mm of said one side of said sheet stack; and/or wherein said electronic stack edge guide repositioning confirmation system provides an operator error signal when said at least one side guide is positioned not more than approximately 3 mm away from said one side of said sheet stack in said sheet stacking tray; and/or further including a separate stack loading sensor for providing an electrical signal in response to the loading of a stack of sheets into said sheet stacking tray, independently of the stack dimensions, and wherein said electronic stack edge guide repositioning confirmation system provides an operator error signal when said at least one side guide is positioned more than approximately 3 mm away from said one side of said sheet stack in said sheet stacking tray or said electrical signal indicative of the loading of a stack of sheets into said sheet stacking tray is provided from said separate stack loading sensor; and/or an improved sheet feeding method in which stacks of print media sheets of variable dimensions may be stacked into and then fed from a sheet stacking tray, said sheet stacking tray having at least one stack edge guide which is manually repositionable for the particular dimensions of the particularly dimensioned stack of print media sheets currently stacked into that sheet stacking tray, in which said repositioning of said at least one stack edge guide to at least closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray automatically provides, with an electrical sensing system that is repositionable with said at least one side guide, electrical information indicative of said at least one repositionable side guide being positioned sufficiently closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray for proper sheet feeding; and/or wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray is provided when said at least one side guide is substantially engaging said at least one side of said particular dimensioned stack in said sheet stacking tray; and/or wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to said at least one side of said particular dimensioned stack in said sheet stacking tray is provided when said at least one side guide is within at approximately 1 mm of said one side of said stack; and/or wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of a particularly dimensioned stack in said sheet stacking tray provides an operator error signal when said at least one side guide is positioned more than approximately 3 mm away from said one side of said stack in said sheet stacking tray; and/or wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray provides an operator error signal when said at least one side guide is positioned more than approximately 3 mm away from said one side of said particular dimensioned stack in said sheet stacking tray in combination with the detection of the loading of a stack into said sheet stacking tray by a separate stack loading sensor; and/or wherein said sensing system comprises an electronic stack edge guide repositioning confirmation system with a repositionable sheet stack edge proximity sensing system that is automatically repositionable with said at least one repositionable sheet stack edge guide, said electronic stack edge guide positioning confirmation system providing with said repositionable sheet stack edge proximity sensing system an automatic warning signal against the feeding of said sheets from said stack with said sheet feeder if said sheet stack edge guide has not been repositioned into at least close proximity to said at least one side of a sheet stack stacked into said sheet stacking tray; and/or wherein an opposing sheet stack edge guide with a separate sheet stack edge proximity sensor is provided in said sheet stacking tray, and wherein both said separate sheet stack edge proximity sensor and said electrical sensing system repositionable with said repositionable side guide both provide electrical signals indicative of respective sides of a stack of sheets loaded therebetween being positioned sufficiently closely adjacent to both said repositionable side guide and said opposing sheet stack edge in said sheet stacking tray for proper sheet feeding.

The disclosed system may be operated and controlled by appropriate operation of conventional control systems. It is well known and preferable to program and execute imaging, printing, paper handling, and other control functions and logic with software instructions for conventional or general purpose microprocessors, as taught by numerous prior patents and commercial products. Such programming or software may, of course, vary depending on the particular functions, software type, and microprocessor or other computer system utilized, but will be available to, or readily programmable without undue experimentation from, functional descriptions, such as those provided herein, and/or prior knowledge of functions which are conventional, together with general knowledge in the software or computer arts. Alternatively, the disclosed control system or method may be implemented partially or fully in hardware, using standard logic circuits or single chip VLSI designs.

The term “reproduction apparatus” or “printer” as used herein broadly encompasses various printers, copiers or multifunction machines or systems, xerographic or otherwise, unless otherwise defined in a claim. The term “sheet” herein refers to a usually flimsy physical sheet of paper, plastic, or other suitable physical substrate for images, whether precut or web fed.

As to specific components of the subject apparatus or methods, or alternatives therefor, it will be appreciated that, as is normally the case, some such components are known per se in other apparatus or applications, which may be additionally or alternatively used herein, including those from art cited herein. For example, it will be appreciated by respective engineers and others that many of the particular components illustrated herein are merely exemplary, and that the same novel motions and functions can be provided by many other known or readily available alternatives. All cited references, and their references, are incorporated by reference herein where appropriate for teachings of additional or alternative details, features, and/or technical background. What is well known to those skilled in the art need not be described herein.

Various of the above-mentioned and further features and advantages will be apparent to those skilled in the art from the specific apparatus and its operation or methods described in the examples below, and the claims. They may be better understood from this description of these specific embodiments, including the drawing figures (which are approximately to scale) wherein:

FIG. 1 is a schematic partial and partially broken away top view of one example of one otherwise conventional sheet tray and its sheet feeder with one example of repositionable stack edge guides and one example of the sensing system described herein to signal proper alignment of the stack edge guides with the particular size of the sheets in the particular stack loaded into the tray at that time; and

FIGS. 2 and 3 are enlarged and partial end views of the embodiment of FIG. 1, with a stack of sheets loaded therein, and with two different respective sensor examples.

Describing now in further detail the exemplary embodiments with reference to the Figures, a general background discussion will first be provided.

The system of the disclosed embodiments add paper stack edge proximity sensors to otherwise conventional or existing (but modified as described) stack side and/or end guides, such as those already provided in most sheet feeder paper trays, drawers or cassettes (these terms may be generically referred to herein as trays). These modifications help to ensure proper positioning of the repositionable stack side and/or end guides (hereinafter referred to herein as stack guides) relative to the stack of sheets being loaded into that particular tray, or a particular stacking area thereof in the case of a tray with more than one stacking area, by the operator or customer. This can provide useful feedback signals if the guides were not reset appropriately relative to the newly loaded stack for good sheet feeding. For example, correct repositioning of the stack guides relative to the particular dimensions of a stack of print media reduces the opportunity for skewed sheet input, which can cause skewed printing and/or paper jams.

As noted, the present system can provide an automatic check and signal confirmation that the stack guides are in fact sufficiently adjacent to the actual stack of sheets then in a particular tray for proper stacking alignment and/or feeding and a fault or warning signal may be provided if the stack guides have not been properly reset to the current stack dimensions. This does not require, or depend on the accuracy of, manual operator input of information on the size of the print media. In particular, the stack dimensions currently loaded in the tray selected for sheet feeding for the current print job, which will be the source of miss-feeds. However, the present system can also provide a GUI signal to the operator of failure to properly reset the stack edge guides immediately at any time, such as immediately after loading sheets into any tray (whether that tray is being currently selected for sheet feeding or not) and/or checking after the closing of that or any sheet stacking tray.

Further by way of background in that respect, when a user inserts a stack of print media sheets into a typical present sheet feeder, little or no automatic feedback is available to the printing system and/or to the user to ensure that the sheets have been inserted correctly or that the stack guides have been adjusted correctly to that particular sheet stack's dimensions. Yet correct adjustment of the stack guides, especially the stack edge guides parallel to the sheet feeding direction, is important for feeding control of the sheets with respect to sheet skew and edge registration. Improperly stacked sheets and/or miss-adjusted stack guides can result in excessive skew or other sheet registration errors, even image misprints, and in some cases, sheet miss-feeds or multi-feeds causing printer jams and shutdowns.

Currently, many trays and sheet feeders employ a “Document Present” (or presence) Sensor (DPS) to simply detect the presence of any size stack of documents loaded into a particular tray stacking area. However, that of course provides no information as to whether or not the stack of sheets is within properly positioned (closely adjacent or contacting) stack guides reset to that particular stack's lateral or length dimensions. The disclosed embodiments adds additional sensors to the paper guides to detect when a paper guide is sufficiently close to the side or end of the stack to ensure correct control of the sheets being fed. Both types of sensors may be checked at the start of a printing run and a logical AND may be applied, such that feeding from the stack would only be initiated if both (or all) sensors are triggered concurrently, thus ensuring that a stack of sheets has been loaded into the tray and that the tray paper guides(s) have been correctly adjusted to that stack. If any one of the sensor inputs is not triggered, a fault condition may be declared, and the user may be directed to correct the condition via the machine's GUI and/or other alarm system, locally or remotely.

In the Figures, there is schematically or partially shown an otherwise typical sheet tray 10 with a sheet stacking area 10A for stacking sheets of different dimensions between repositionable stack edge guides 12A and 12B for feeding those sheets with a sheet feeder 20, and an added stack edge guide stack proximity sensor 40, which may be connected to an otherwise conventional printer or feeder module controller 100, optionally along with the DPS sensor 30 noted above. The sheet feeder 20 assembly for this tray 10 is shown in a partially cut-away view with feed rolls 22, 24, and also showing one example of an approximate placement of the DPS sensor 30. The controller 100, and the printer 200 to which the sheets are being sequentially fed to be printed from selected stacks thereof in the tray 10 or other trays, may be otherwise conventional and thus are only shown schematically here.

For a side-registered system, one of the stack edge or side guides may be a fixed or stationary wall surface. However, in this particular (known) example of FIG. 1, as in the above-incorporated patents, the two movable (side) guides 12A and 12B are examples of stack edge guides suitable for a center-registered sheet feeding system. Thus, the two stack edge guides 12A and 12B may be mechanically linked or synchronized to move toward or away from each other in unison, such as by the rack and pinion linkage shown in FIG. 1 or shown in those above-cited patents. In this case, it is possible to only add one sensing system 40 to only one of the two stack edge guides (12B here), on only one side of the stacking area 10A, yet still ensure that both side guides are moved to within the desired proximity of both sides of the loaded document stack. In the case of a side-registered feeder, with one fixed and one movable guide, the sensing system 40 may be located in the movable stack edge guide.

It will be appreciated by those in the art that the stack edge guides may optionally or additionally provide an edge tamping function in some types of sheet feeders. It will also be appreciated, as shown for example in the above-incorporated patents, that electrical signals corresponding to the approximate reset position of the stack edge guides such as 12B may also be automatically provided, such as from stack edge guide position sensors under the stacking tray, such individual sensors, a variable resistance strip, or a multiple sensors array such as 44 shown in FIG. 1. However, if the particular paper tray does not have such edge guide position sensors, then the subject sensing system may provide the only information to the printer than that the stack edge guides have been reset to the dimensions of the sheet stack being fed from. Even if the system does have edge guide position sensors, such as 44, that typically does not provide sufficiently accurate enough positional information about the desired close spacing of the edge guide from the edge of the stack for optimum sheet feeding, even if the standardized dimensions of the stack being loaded had been accurately manually entered into the controller 100, such as “letter size,” “A4,” and the like. Actual sheet dimensions can vary due to manufacturing sheet cutting tolerances and humidity. Also, typically the stack edge guide movement system for its repositioning is simple and low cost, with considerable movement tolerances relative to the tray, whereas the subject sensors are independent of that because the sensing elements are on the actual vertical sheet guiding surface of the stack edge guide itself, repositioned with the repositioning of the stack edge guide, and are approximately sensing the actual distance between that sheet guiding surface of the stack edge guide and the actual sheet stack edge, that is, when they are sufficiently close enough to one another for optimum sheet feeding, or not.

Referring further to FIGS. 2 and 3, it will be appreciated that the stack edge guide stack proximity sensing system 40 may be of a suitable type to make initial direct or indirect contact with the side 14 of the document stack facing the side guide 12B on which it is mounted, and with which it moves. Alternatively, as shown in FIGS. 2 and 3, the stack edge guide stack proximity sensor 40 may be of a non-contact but close spacing detecting type, such as the lever switch 44 with actuating arm 44A of FIGS. 1 and 2, or the vertical array of multiple optical sensors 50 of FIG. 3. Both of these sensors 44 and 50 may be provided with an elongated vertical detection area as shown to provide for better detection of the appropriate edge guide setting position for an irregular stack in which some sheet edges may stick out laterally from the stack more than other sheets at different levels in the stack height.

Although not limited thereto, it is believed that confirming via the subject stack edge guide sensor system 40 or the like that a stack edge guide has been accurately reset to within approximately 1 mm of the side of the stack, or not more than 2 mm away per side, should provide satisfactory sheet feeding in most cases from most stacks with most sheet feeders.

Regardless of whether the system is center or side registered, preferably both side guides need the subject stack edge proximity sensors. Otherwise an operator could install a smaller size print media stack biased to only the one side guide having the proximity sensor and fool the system, even if the other side of the stack is spaced a long distance away from the opposing side guide because the operator failed to reset the side guides to engage both sides of the stack upon loading the new stack. (Of course in a side-registered system one of the side guides may be a fixed position vertical side wall of the tray.) A logical “AND” decision gate signal based on the inputs from both of the side guides sensors and the DPS can ensure that documents are inserted fully prior to job start and the side guides properly reset to the stack size.

The same basic operational principles may be applied if a repositionable stack end or length guide or guides such as 15 in FIG. 1 are also provided in the tray 10. In that case, additional such sensing systems, such as the above sensing system 40, may be additionally provided on the repositionable end guide 15 and also connected to the controller 100 for concurrent triggering to automatically signal proper positioning of all the stack edge guides to the particular dimensions of the stack loaded into the tray at that time.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. 

1. In a sheet stacking tray for stacking print media sheets of different sheet stack dimensions in at least one sheet stacking area for feeding said sheets from said stack with a sheet feeder, said sheet stacking tray having at least one manually repositionable sheet stack edge guide repositionable to provide an edge guide for at least one side of said sheet stack for said different particular sheet stack dimensions, there is provided an electronic stack edge guide positioning confirmation system with a repositionable sheet stack edge proximity sensing system that is automatically repositionable with said at least one repositionable sheet stack edge guide, said electronic stack edge guide repositioning confirmation system providing with said repositionable sheet stack edge proximity sensing system an automatic warning signal against the feeding of said sheets from said stack with said sheet feeder if said sheet stack edge guide has not been positioned in at least close proximity to said at least one side of said sheet stack sheet stack stacked into said sheet stacking tray.
 2. The sheet stacking tray of claim 1 wherein said electronic stack edge guide repositioning confirmation system is adapted to provide electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of said sheet stack in said sheet stacking tray to substantially engage said at least one side of said stack in said sheet stacking tray.
 3. The sheet stacking tray of claim 1 wherein said electronic stack edge guide repositioning confirmation system is adapted to provide electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to said at least one side of said sheet stack in said sheet stacking tray when said at least one side guide is positioned within approximately 2 mm of said one side of said sheet stack.
 4. The sheet stacking tray of claim 1 wherein said electronic stack edge guide repositioning confirmation system provides an operator error signal when said at least one side guide is positioned not more than approximately 3 mm away from said one side of said sheet stack in said sheet stacking tray.
 5. The sheet stacking tray of claim 1, further including a separate stack loading sensor for providing an electrical signal in response to the loading of a stack of sheets into said sheet stacking tray, independently of the stack dimensions, and wherein said electronic stack edge guide repositioning confirmation system provides an operator error signal when said at least one side guide is positioned more than approximately 3 mm away from said one side of said sheet stack in said sheet stacking tray or said electrical signal indicative of the loading of a stack of sheets into said sheet stacking tray is provided from said separate stack loading sensor.
 6. An improved sheet feeding method in which stacks of print media sheets of variable dimensions may be stacked into and then fed from a sheet stacking tray, said sheet stacking tray having at least one stack edge guide which is manually repositionable for the particular dimensions of the particularly dimensioned stack of print media sheets currently stacked into that sheet stacking tray, in which said repositioning of said at least one stack edge guide to at least closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray automatically provides, with an electrical sensing system that is repositionable with said at least one side guide, electrical information indicative of said at least one repositionable side guide being positioned sufficiently closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray for proper sheet feeding.
 7. The improved sheet feeding method of claim 6 wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray is provided when said at least one side guide is substantially engaging said at least one side of said particular dimensioned stack in said sheet stacking tray.
 8. The improved sheet feeding method of claim 6 wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to said at least one side of said particular dimensioned stack in said sheet stacking tray is provided when said at least one side guide is within at approximately 1 mm of said one side of said stack.
 9. The improved sheet feeding method of claim 6 wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of a particularly dimensioned stack in said sheet stacking tray provides an operator error signal when said at least one side guide is positioned more than approximately 3 mm away from said one side of said stack in said sheet stacking tray.
 10. The improved sheet feeding method of claim 6 wherein said sensing system providing electrical information indicative of said at least one side guide being positioned sufficiently closely adjacent to at least one side of said particular dimensioned stack in said sheet stacking tray provides an operator error signal when said at least one side guide is positioned more than approximately 3 mm away from said one side of said particular dimensioned stack in said sheet stacking tray in combination with the detection of the loading of a stack into said sheet stacking tray by a separate stack loading sensor.
 11. The improved sheet feeding method of claim 6 wherein said sensing system comprises an electronic stack edge guide repositioning confirmation system with a repositionable sheet stack edge proximity sensing system that is automatically repositionable with said at least one repositionable sheet stack edge guide, said electronic stack edge guide positioning confirmation system providing with said repositionable sheet stack edge proximity sensing system an automatic warning signal against the feeding of said sheets from said stack with said sheet feeder if said sheet stack edge guide has not been repositioned into at least close proximity to said at least one side of a sheet stack stacked into said sheet stacking tray.
 12. The improved sheet feeding method of claim 6 wherein an opposing sheet stack edge guide with a separate sheet stack edge proximity sensor is provided in said sheet stacking tray, and wherein both said separate sheet stack edge proximity sensor and said electrical sensing system repositionable with said repositionable side guide both provide electrical signals indicative of respective sides of a stack of sheets loaded therebetween being positioned sufficiently closely adjacent to both said repositionable side guide and said opposing sheet stack edge in said sheet stacking tray for proper sheet feeding. 